Masses of vector bosons in two-color dense QCD based on the hidden local symmetry

We construct a low-energy effective Lagrangian for the two-color QCD including the "vector'' bosons (mesons with J(P) = 1(-) and diquark baryons with J(P) = 1(+)) in addition to the pseudo-Nambu-Goldstone bosons with a degenerate mass M-pi (mesons with J(P) = 0(-) and baryons with J(P) = 0(+)) based on the chiral symmetry breaking pattern of SU(2N(f)) -> Sp(2N(f)) in the framework of the hidden local symmetry. We investigate the dependence of the vector boson masses on the baryon number density mu B. We show that the mu B-dependence signals the phase transition of U(1)(B) breaking. We find that it gives information about mixing among vector bosons: e. g. the mass difference between "rho'' and "omega'' mesons is proportional to the mixing strength between the diquark baryon with J(P) = 1(+) and the antibaryon. We discuss the comparison with lattice data for two-color QCD at finite density.